Heat exchanging element

ABSTRACT

A lamination type heat exchanging element for use in heat exchange type ventilators and other air conditioning devices eliminates drift in the air passages while maintaining its structural strength, thereby providing high heat exchange efficiency. The heat exchanging element also prevents airflow leakage due to peeling between heat exchanger plates and other components. To achieve this, rectification portions are provided which eliminate drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions.

TECHNICAL FIELD

The present invention relates to a lamination type heat exchanging element for use in heat exchange type ventilation fans for domestic use, in heat exchange type ventilators for buildings and other structures, and in other air conditioning devices.

BACKGROUND ART

A conventional heat exchanging element is described as follows with reference to FIGS. 12A and 12B. FIG. 12A is a schematic perspective view of a conventional heat exchanger. FIG. 12B is a partial sectional view of the conventional heat exchanger.

As shown in FIG. 12A, conventional heat exchanger 101 includes pairs of plates 102, each pair being opposite to and predeterminedly spaced from each other. Between each pair of plates 102 is arranged planer fin 104 having a corrugated cross section so as to form parallel flow channels 103. Adjacent pairs of plates 102 are spaced by spacers 105 for guiding primary airflow “M” and secondary airflow “N”. Heat exchanger 101 further includes space portions 106 on the downstream side of parallel flow channels 103 formed by fins 104. Fins 104 and spacers 105 are glued to plates 102.

Heat exchanger 101 includes inlet ports for receiving primary and secondary airflows “M” and “N” on opposite sides thereof, and outlet ports for discharging the airflows “M” and “N” on a side perpendicular to the sides of the inlet ports. The side opposite to the side of the outlet ports is closed. As shown in FIG. 12B, fins 104 are formed at increasingly smaller pitch “P” from one side (the left side in FIG. 12B) to the other (the right side in FIG. 12B) on which the outlet ports are formed. This causes a change in the cross sectional area of parallel flow channels 103, thereby improving the heat exchange efficiency of heat exchanger 101.

In conventional heat exchanger 101, space portions 106 formed on the downstream side of parallel flow channels 103 cause drift inside them because of the absence of components to control airflow. In addition, space portions 106 are too low-strength to maintain the spacing between adjacent plates 102 because of the absence of components to maintain the spacing. This causes primary and secondary airflows “M” and “N” circulating through heat exchanger 101 to drift, thereby decreasing the heat exchange efficiency. Thus, there is a demand for improving both strength and heat exchange efficiency.

In order to reduce the cross sectional area of regions of parallel flow channels 103 that are close to the side on which the outlet ports are formed, the number of junctions between plates 102 and fins 104 is made larger than necessary to maintain the structure of parallel flow channels 103. These junctions cause a decrease in the effective area of the heat exchanger plates. Moreover, the adhesive used to join plates 102 and fins 104 protrudes from the junctions, thereby significantly reducing the effective area of plates 102, and hence, the heat exchange efficiency. Thus, there is a demand for improving the heat exchange efficiency.

In the case where parallel flow channels 103 are formed by arranging independent components on plates 102 instead of fins 104, the width of the flow channel having the largest pitch “P” of parallel flow channels 103 cannot be made larger than the largest pitch “P” with which to maintain the structure of parallel flow channels 103. Furthermore, the design with increasingly smaller pitch “P” causes the number of parallel flow channels 103 to be larger than necessary to maintain the structure of parallel flow channels 103, thereby significantly reducing the effective area of plates 102, and hence the heat exchange efficiency. Thus, there is a demand for improving the heat exchange efficiency.

Since fins 104 and spacers 105 are inserted into between plates 102 and glued thereto, the distance between the top and bottom of the corrugation of fins 104 and the thickness of spacers 105 should be highly uniform. However, in the actual production process, it is difficult to make them uniform because fins 104 have uneven pitch “P”. Fins 104 having a large distance between the top and bottom of the corrugation are crushed when glued to plates 102, while fins 104 having a small distance cannot be properly glued to plates 102. This makes it impossible to achieve the designed pitch “P”. Furthermore, the poor precision in the thickness direction causes the heat exchanger plates to bend, and the difference in height of pairs of plates 102 causes drift in the heat exchanging element, thereby reducing the heat exchange efficiency. Thus, there is a demand for improving the heat exchange efficiency.

Heat exchanger 101 includes low-strength space portions 106 and parallel flow channels 103 formed with pitch “P” increasingly decreasing from one side to the other on which the outlet ports are formed. As a result, heat exchanger 101 is subjected to variations in strength and hence deformation. The deformation can cause peeling between plates 102 and fins 104 or between plates 102 and spacers 105, thereby increasing airflow leakage. Thus, there is a demand for preventing airflow leakage.

Patent Document 1: Japanese Patent Examined Publication No. S60-238689

SUMMARY OF THE INVENTION

In view of the conventional problems, it is an object of the present invention to provide a heat exchanging element that eliminates drift in air passages while maintaining its structural strength, thereby providing high heat exchange efficiency and that also prevents airflow leakage due to peeling between the heat exchanger plates and other components.

The heat exchanging element according to the present invention performs heat exchange by circulating a primary airflow and a secondary airflow through their corresponding air passages alternately formed between a plurality of heat exchanger plates laminated on each other with a predetermined spacing. The heat exchanging element includes counterflow regions in which the primary airflow and the secondary airflow flow opposite to each other with the heat exchanger plates therebetween. The heat exchanging element further includes shield portions for preventing airflow leakage from regions other than the inlet and outlet ports of the primary and secondary airflows in the air passages; flow channel division portions for dividing each of the air passages into a plurality of flow channels, the flow channels divided by the flow channel division portions having different flow channel lengths from each other; and rectification portions arranged in the air passages, the rectification portions providing a predetermined flow velocity distribution of the primary and secondary airflows circulating through the counterflow regions in the flow channels divided by the flow channel division portions.

Thus, the present invention provides a heat exchanging element that eliminates drift in the air passages while maintaining its structural strength, thereby providing high heat exchange efficiency, and that also prevents airflow leakage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a heat exchanging element according to a first embodiment of the present invention.

FIG. 2A is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 1.

FIG. 2B is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction Y of FIG. 1.

FIG. 3 is a schematic production flowchart of the heat exchanging element according to the first embodiment of the present invention.

FIG. 4 is a schematic perspective view of a heat exchanging element according to a second embodiment of the present invention.

FIG. 5A is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 4.

FIG. 5B is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction Y of FIG. 4.

FIG. 6 is a schematic perspective view of a heat exchanging element according to a third embodiment of the present invention.

FIG. 7 is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 6.

FIG. 8 is a schematic production flowchart of the heat exchanging element according to the third embodiment of the present invention.

FIG. 9 is a schematic perspective view of a heat exchanging element according to a fourth embodiment of the present invention.

FIG. 10A is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 9.

FIG. 10B is an enlarged schematic perspective view of one unit element as a component of the heat exchanging element seen in the direction X of FIG. 9.

FIG. 10C is an enlarged schematic perspective view of the unit element taken along line A-A of FIG. 10B.

FIG. 11 is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction Y of FIG. 9.

FIG. 12A is a schematic perspective view of a conventional heat exchanger.

FIG. 12B is a partial sectional view of the conventional heat exchanger.

REFERENCE MARKS IN THE DRAWINGS

-   1 a, 1 b, 1 c, 1 d heat exchanging element -   2 a, 2 b, 2 c, 2 d, 2 e, 2 f resin frame -   3 a, 3 b, 3 c, 3 d heat exchanger plate -   4 a, 4 b, 4 c, 4 d, 4 e, 4 f, 4 g, 4 h unit element -   5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H air passage -   6 a, 6 b, 6 c, 6 d, 6 e, 6 f, 6 g, 6 h shield portion -   7 a, 7 b, 7 c, 7 d, 7 e, 7 f, 7 g, 7 h flow channel division portion -   8 a, 8 b, 8 c, 8 d, 8 e, 8 f, 8 g, 8 h rectification portion -   9 a, 9 b, 9 c, 9 d, 9 e, 9 f engagement projection -   10 a, 10 b, 10 c, 10 d, 10 e, 10 f engagement recess -   11 a, 11 b, 11 c, 11 d, 11 e, 11 f, 11 g, 11 h inlet port -   12 a, 12 b, 12 c, 12 d, 12 e, 12 f, 12 g, 12 h outlet port -   13 a, 13 b, 13 c, 13 d, 13 e, 13 f, 13 g, 13 h, 13 i, 13 j, 13 k, 13     m, 13 n, 13 p, 13 q, 13 r, 13 s, 13 t, 13 u, 13 v, 13 w, 13 x, 13 y,     13 z flow channel -   14 a, 14 b, 14 c, 14 d counterflow region -   15 a, 15 b cutting step -   16 a, 16 b molding step -   17 a, 17 b laminating step -   18 a, 18 b bonding step -   19 a, 19 b spaced projection

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A heat exchanging element according to the present invention performs heat exchange by circulating a primary airflow and a secondary airflow through their corresponding air passages alternately formed between a plurality of heat exchanger plates laminated on each other with a predetermined spacing, the heat exchanging element including: counterflow regions in which the primary and secondary airflows flow opposite to each other with the heat exchanger plates therebetween; shield portions for preventing airflow leakage from regions other than the inlet and outlet ports of the primary and secondary airflows in the air passages; flow channel division portions for dividing each of the air passages into a plurality of flow channels, the flow channels divided by the flow channel division portions having different flow channel lengths from each other; and rectification portions arranged in the air passages, the rectification portions providing a predetermined flow velocity distribution of the primary and secondary airflows circulating through the counterflow regions in the flow channels divided by the flow channel division portions.

The heat exchanging element has less drift in the air passages because the air passages are each divided into a plurality of flow channels by the flow channel division portions. The different flow channel lengths of the flow channels divided by the flow channel division portions result in their different ventilation resistances, thereby causing drift in the air passages. The drift, however, is eliminated by providing the rectification portions in the air passages so as to change the ventilation resistances of the flow channels and to form a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency while maintaining the structural strength of the heat exchanging element. The flow channel division portions play a role in maintaining both the spacing between the heat exchanger plates and the strength of the heat exchanging element, so that the spacing between the heat exchanger plates can be kept uniform. This prevents drift due to uneven spacing between the heat exchanger plates, which have a low structural strength, thereby providing high heat exchange efficiency while maintaining the structural strength of the heat exchanging element.

In the heat exchanging element, the rectification portions may be located somewhere in the air passages other than the counterflow regions.

Thus locating the rectification portions somewhere in the air passages other than the counterflow regions having the greatest effect on the heat exchange efficiency of the heat exchanging element can change the ventilation resistances of the flow channels divided by the flow channel division portions while reducing the effect on the heat exchange efficiency. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be ventilation resistance members shaped to increase ventilation resistances of the flow channels other than the longest flow channel having the longest flow channel length of all the flow channels divided by the flow channel division portions.

The longest flow channel has a higher ventilation resistance than the other flow channels. Therefore, the flow channels other than the longest flow channel are provided with the rectification portions, which are the ventilation resistance members to increase their ventilation resistances. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be partially or wholly located in the inlet ports of the flow channels other than the longest flow channel so that the opening area of each of the inlet ports of the flow channels other than the longest flow channel can be smaller than the opening area of the inlet port of the longest flow channel.

The longest flow channel has a higher ventilation resistance than the other flow channels. Therefore, the flow channels other than the longest flow channel are provided in their inlet ports with the rectification portions so as to reduce the opening area of each of the inlet ports including the rectification portions, thereby increasing their ventilation resistances. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be partially or wholly located in the outlet ports of the flow channels other than the longest flow channel so that the opening area of each of the outlet ports of the flow channels other than the longest flow channel can be smaller than the opening area of the outlet port of the longest flow channel.

The longest flow channel has a higher ventilation resistance than the other flow channels. Therefore, the flow channels other than the longest flow channel are provided in their outlet ports with the rectification portions so as to reduce the opening area of each of the outlet ports including the rectification portions, thereby increasing their ventilation resistances. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be partially or wholly located in the inlet and outlet ports of the flow channels other than the longest flow channel so that the opening area of each of the inlet ports and the opening area of each of the outlet ports of the flow channels other than the longest flow channel can be smaller than the opening area of the inlet port and the opening area of the outlet port, respectively, of the longest flow channel.

The longest flow channel has a higher ventilation resistance than the other flow channels. Therefore, the flow channels other than the longest flow channel are provided in their inlet and outlet ports with the rectification portions so as to reduce the opening area of each of the inlet ports and the opening area of each of the outlet ports including the rectification portions, thereby increasing their ventilation resistances. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be shaped to decrease ventilation resistances of the flow channels having flow channel lengths longer than an average flow channel length of the flow channels divided by the flow channel division portions and to increase ventilation resistances of the flow channels having flow channel lengths shorter than the average flow channel length.

Thus, the rectification portions are provided so as to decrease ventilation resistances of the flow channels having flow channel lengths longer than the average flow channel length, and to increase ventilation resistances of the flow channels having flow channel lengths shorter than the average flow channel length. This increases the flow velocities of the flow channels having flow channel lengths longer than the average flow channel length and decreases the flow velocities of the flow channels having flow channel lengths shorter than the average flow channel length. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be partially or wholly located in the inlet ports of the flow channels so that the opening area of each of the inlet ports of the flow channels having longer flow channel lengths than the average flow channel length can be larger than the average opening area of the inlet ports, and that the opening area of each of the inlet ports of the flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area of the inlet ports.

The flow channels having flow channel lengths longer than the average flow channel length relatively have large ventilation resistances and low flow velocities. The flow channels having flow channel lengths shorter than the average flow channel length relatively have small ventilation resistances and high flow velocities. However, the provision of the rectification portions in the inlet ports allows the opening area of each of the inlet ports of the flow channels having flow channel lengths longer than the average flow channel length to be larger than the average opening area of the inlet ports, thereby decreasing their ventilation resistances. The provision of the rectification portions in the inlet ports also allows the opening area of each of the inlet ports of the flow channels having flow channel lengths shorter than the average flow channel length to be smaller than the average opening area of the inlet ports, thereby increasing their ventilation resistances. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be partially or wholly located in the outlet ports of the flow channels so that the opening area of each of the outlet ports of the flow channels having longer flow channel lengths than the average flow channel length can be larger than the average opening area of the outlet ports, and that the opening area of each of the outlet ports of the flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area of the outlet ports.

The flow channels having flow channel lengths longer than the average flow channel length relatively have large ventilation resistances and low flow velocities. The flow channels having flow channel lengths shorter than the average flow channel length relatively have small ventilation resistances and high flow velocities. However, the provision of the rectification portions in the outlet ports allows the opening area of each of the outlet ports of the flow channels having flow channel lengths longer than the average flow channel length to be larger than the average opening area of the outlet ports, thereby decreasing their ventilation resistance. The provision of the rectification portions in the outlet ports also allows the opening area of each of the outlet ports of the flow channels having flow channel lengths shorter than the average flow channel length to be smaller than the average opening area of the outlet ports, thereby increasing their ventilation resistance. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions may be partially or wholly located in the inlet and outlet ports of the flow channels so that the opening area of each of the inlet ports and the opening area of each of the outlet ports of the flow channels having longer flow channel lengths than the average flow channel length can be larger than the average opening area of the inlet ports and the average opening area of the outlet ports, respectively, and that the opening area of each of the inlet ports and the opening area of each of the outlet ports of the flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area of the inlet ports and the average opening area of the outlet ports, respectively.

The flow channels having flow channel lengths longer than the average flow channel length relatively have large ventilation resistances and low flow velocities. The flow channels having flow channel lengths shorter than the average flow channel length relatively have small ventilation resistances and high flow velocities. However, the provision of the rectification portions in the inlet and outlet ports allows the opening area of each of the inlet ports and the opening area of each of the outlet ports of the flow channels having flow channel lengths longer than the average flow channel length to be larger than the average opening area of the inlet ports and the average opening area of the outlet ports, respectively, thereby decreasing their ventilation resistances. The provision of the rectification portions in the inlet and outlet ports also allows the opening area of each of the inlet ports and the opening area of each of the outlet ports of the flow channels having flow channel lengths shorter than the average flow channel length to be smaller than the average opening area of the inlet ports and the average opening area of the outlet ports, respectively, thereby increasing their ventilation resistances. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the flow channel division portions may be partially integrated with the rectification portions, and the rectification portions may be formed by bending parts of the flow channel division portions in such a manner that the opening area of flow channels having longer flow channel lengths than the average flow channel length of the flow channels divided by the flow channel division portions can be larger than the average opening area, and that the opening area of flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area.

The flow channels having flow channel lengths longer than the average flow channel length relatively have large ventilation resistances and low flow velocities. The flow channels having flow channel lengths shorter than the average flow channel length relatively have small ventilation resistances and high flow velocities. However, the opening area of the flow channels having flow channel lengths longer than the average flow channel length can be larger than the average opening area so as to decrease their ventilation resistances, thereby increasing the flow velocities. The opening area of the flow channels having flow channel lengths shorter than the average flow channel length can be smaller than the average opening area so as to increase their ventilation resistances, thereby decreasing the flow velocities. The rectification portions, which are formed by bending parts of the flow channel division portions, hardly decrease the effective area of the heat exchanger plates or do not decrease the total opening area of the inlet ports or the outlet ports. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. This results in providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions that increase ventilation resistances of the flow channels divided by the flow channel division portions may be integrally formed with the flow channel division portions, the rectification portions being formed as projections on the surfaces of the flow channel division portions that are in contact with the flow channels.

Thus forming the projections as the rectification portion on the surfaces of the flow channel division portions that are in contact with the flow channels makes it possible to determine the ventilation resistance of each flow channel freely. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. Furthermore, the projections eliminate drift in each flow channel, thereby providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions that increase ventilation resistances of the flow channels divided by the flow channel division portions may be integrally formed with the shield portions, the rectification portions being formed as projections on some or all surfaces of the shield portions that are in contact with the opening sections of the flow channels.

Thus forming the projections on the surfaces of the shield portions that are in contact with the opening sections makes it possible to determine the ventilation resistance of each flow channel freely. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. Furthermore, the projections eliminate drift in each flow channel, thereby providing high heat exchange efficiency.

In the heat exchanging element, the projections may be high on the opening side and low on the inner side.

Making the projections high on the opening side and low on the inner side can eliminate drift in the air passages while minimizing airflow disorder due to abrupt expansion or contraction of the flow channels, thereby forming a predetermined flow velocity distribution in the counterflow regions. Furthermore, the projections eliminate drift in each flow channel, thereby providing high heat exchange efficiency.

In the heat exchanging element, the rectification portions that increase ventilation resistances of the flow channels divided by the flow channel division portions may be formed as projections on the heat exchanger plates.

Thus forming the projections on the heat exchanger plates makes it possible to determine the ventilation resistance of each flow channel freely. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. Furthermore, the projections eliminate drift in each flow channel, thereby providing high heat exchange efficiency.

In the heat exchanging element, the projections may be formed between one side surface of the heat exchanger plates and a reverse side of the flow channel division portions.

Thus forming the projections between one side surface of the heat exchanger plates and a reverse side of the flow channel division portions makes it possible to determine the ventilation resistance of each flow channel freely without decreasing the effective area of the heat exchanger plates. This eliminates drift in the air passages due to different ventilation resistances of the flow channels caused by their different flow channel lengths generated by the flow channel division portions, thereby forming a predetermined flow velocity distribution in the counterflow regions. Furthermore, the projections eliminate drift in each flow channel, thereby providing high heat exchange efficiency.

In the heat exchanging element, the heat exchanger plates may be integrally molded with resin frames using an injection molding process so as to form a plurality of unit elements, the heat exchanger plates being made of paper or resin and having heat conductivity, moisture permeability, and a gas shielding property, the resin frames being made of synthetic resin and forming the air passages including the shield portions, the flow channel division portions, and the rectification portions, and the plurality of unit elements being laminated on each other.

Each of the heat exchanger plates is inserted into an injection mold for molding resin frames, and molten resin is injected into the mold so that resin frames are integrally molded with the heat exchanger plate. This improves the joint strength between the heat exchanger plate and the resin frames each having the shield portions, the flow channel division portions, and the rectification portions. As a result, this prevents airflow leakage due to peeling between the heat exchanger plate and the resin frames. The use of the injection molding process to integrally mold the shield portions, the flow channel division portions, and the rectification portions provides high-precision spacing between the heat exchanger plates in the thickness direction. This enables the heat exchanging element to maintain its strength, thus preventing bending of the heat exchanger plates, which may be caused if the precision in the thickness direction is low while the unit elements are alternately laminated, and also preventing drift in the air passages which may be caused when the unit elements do not have a uniform height. This results in providing high heat exchange efficiency.

In the heat exchanging element, the heat exchanger plates made of thermoplastic resin may be each provided with an uneven surface structure so as to form the unit elements, the unit elements being laminated on each other.

The unit elements are formed by providing an uneven surface structure on the heat exchanger plates of thermoplastic resin by vacuum forming or the like. The heat exchanger plates, the shield portions, the flow channel division portions, and the rectification portions are all made of the same material. This prevents peeling between the heat exchanger plates and other components, and hence, airflow leakage due to peeling. The integral molding of the shield portions, the flow channel division portions, and the rectification portions provides high-precision spacing between the heat exchanger plates in the thickness direction. This enables the heat exchanging element to maintain its strength, thus preventing bending of the heat exchanger plates, which may be caused if the precision in the thickness direction is low while the unit elements are alternately laminated, and also preventing drift in the air passages which may be caused when the unit elements do not have a uniform height. This results in providing high heat exchange efficiency.

In the heat exchanging element, the primary airflow and the secondary airflow circulating the flow channels divided by the flow channel division portions may be subjected to heat exchange in order of being at a right angle or an oblique angle to each other, being opposite to each other, and being at a right angle or an oblique angle to each other with the heat exchanger plates therebetween.

The presence of the regions in which the primary airflow and the secondary airflow flow opposite to each other with the heat exchanger plates therebetween provides high heat exchange efficiency.

In the heat exchanging element, the heat exchanging element may have a rectangular picture plane in the lamination direction, the inlet ports of the primary airflow on the short side, the inlet ports of the secondary airflow on the other short side, and the outlet ports of the primary airflow and the outlet ports of the secondary airflow on the long side.

The primary airflow is drawn in from the short side and drawn out from a portion of the long side. The secondary airflow is drawn in from the short side opposite to the side on which the inlet ports of the primary airflow are formed, and is drawn out from a portion of the long side on which the outlet ports of the primary airflow are formed. The rectangular picture plane of the heat exchanging element in the lamination direction allows the primary and secondary airflows to flow opposite to each other in long regions with the heat exchanger plates therebetween, thereby providing high heat exchange efficiency.

The embodiments of the present invention will be described as follows with reference to drawings.

First Embodiment

FIG. 1 is a schematic perspective view of a heat exchanging element according to a first embodiment of the present invention. FIG. 2A is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 1. FIG. 2B is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction Y of FIG. 1. FIG. 3 is a schematic production flowchart of the heat exchanging element.

As shown in FIGS. 1, 2A, and 2B, heat exchanging element 1 a includes unit elements 4 a and unit elements 4 b alternately laminated on each other. Each unit element 4 a includes heat exchanger plate 3 a integrally molded with resin frame 2 a. Each unit element 4 b includes heat exchanger plate 3 a integrally molded with resin frame 2 b. Each heat exchanger plate 3 a includes air passage 5A on its top surface and air passage 5B on its bottom surface. Heat exchanging element 1 a circulates primary airflow “A” through air passage 5A, and secondary airflow “B” through air passage 5B, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 a.

Unit elements 4 a are each formed by integrally molding heat exchanger plate 3 a with resin frame 2 a including shield portions 6 a, flow channel division portions 7 a, rectification portions 8 a, engagement projections 9 a, and engagement recesses 10 a. Unit elements 4 b are each formed by integrally molding heat exchanger plate 3 a with resin frame 2 b including shield portions 6 b, flow channel division portions 7 b, rectification portions 8 b, engagement projections 9 b, and engagement recesses 10 b. Unit elements 4 a and 4 b have a picture plane with a long side of 145 mm and a short side of 65 mm in the lamination direction.

The alternate lamination of unit elements 4 a and unit elements 4 b enables heat exchanging element 1 a to have inlet ports 11 a and outlet ports 12 a of primary airflow “A” and inlet ports 11 b and outlet ports 12 b of secondary airflow “B”. Air passage 5A is divided into three flow channels 13 a, 13 b, and 13 c by flow channel division portions 7 a. Air passage 5B is divided into three flow channels 13 d, 13 e, and 13 f by flow channel division portions 7 b.

Shield portions 6 a and 6 b are arranged on the top and bottom surfaces, respectively, of heat exchanger plate 3 a so as to form the outer frames excluding inlet ports 11 a, 11 b and outlet ports 12 a, 12 b. The linear portions of shield portions 6 a and 6 b have a width of 4 mm and a height of 0.75 mm.

Flow channel division portions 7 a and 7 b, which have a width of 1.5 mm and a height of 0.75 mm, are arranged on the top and bottom surfaces, respectively, of heat exchanger plate 3 a so as to fit each other when unit elements 4 a and 4 b are laminated. Rectification portions 8 a, which have a width of 1.5 mm and a height of 0.75 mm, are integrally formed with flow channel division portions 7 a by bending flow channel division portions 7 a in the vicinity of inlet ports 11 a, 11 b and outlet ports 12 a, 12 b. Rectification portions 8 b, which have a width of 1.5 mm and a height of 0.75 mm, are integrally formed with flow channel division portions 7 b by bending flow channel division portions 7 b in the vicinity of inlet ports 11 a, 11 b and outlet ports 12 a, 12 b. As a result, rectification portions 8 a and 8 b are conformed to each other when unit elements 4 a and 4 b are laminated.

Rectification portions 8 a and 8 b are formed by bending flow channel division portions 7 a and 7 b in the following conditions. The opening area of each of inlet and outlet ports 11 a, 12 a of flow channel 13 a, and the opening area of each of inlet and outlet ports 11 b, 12 b of flow channel 13 d which have a flow channel length longer than the average flow channel length are made larger than the average opening area. The opening area of each of inlet and outlet ports 11 a, 12 a of flow channels 13 b, 13 c and the opening area of each of inlet and outlet ports 11 b, 12 b of flow channels 13 e, 13 f which have flow channel lengths shorter than the average flow channel length are made smaller than the average opening area.

The “flow channel length” in the present specification indicates the center-line length of each flow channel. The flow channel lengths in the present embodiment are as follows: flow channels 13 a and 13 d: 182 mm, flow channels 13 b and 13 e: 142 mm, and flow channels 13 c and 13 f: 105 mm. The average flow channel length is 143 mm. The “opening area” in the present specification indicates the area of the inlet or outlet port of one flow channel. The “total opening area” indicates the sum of the opening areas of the inlet ports or outlet ports of the flow channels of one unit element. The “average opening area” indicates an area obtained by dividing the total opening area by the number of flow channels. The opening areas in the present embodiment are as follows: inlet ports 11 a and 11 b respectively of flow channel 13 a and 13 d: 40.5 mm²; outlet ports 12 a and 12 b respectively of flow channels 13 a and 13 d: 36 mm²; inlet ports 11 a and 11 b respectively of flow channels 13 b and 13 e: 24 mm²; outlet ports 12 a and 12 b respectively of flow channels 13 b and 13 e: 25.5 mm²; inlet ports 11 a and 11 b respectively of flow channels 13 c and 13 f: 16.5 mm²; and outlet ports 12 a and 12 b respectively of flow channels 13 c and 13 f: 19.5 mm². The total opening area of inlet ports 11 a, 11 b and the total opening area of outlet ports 12 a, 12 b are both 81 mm². The average opening area of inlet ports 11 a, 11 b, and the average opening area of outlet ports 12 a, 12 b are both 27 mm².

Engagement projections 9 a and 9 b, which have a width of 1.5 mm and a height of 0.4 mm, are arranged on shield portions 6 a and 6 b, respectively formed on the top surface of each heat exchanger plate 3 a. Engagement recesses 10 a and 10 b, which have a width of 1.6 mm and a depth of 0.5 mm, are arranged on shield portions 6 a and 6 b, respectively formed on the bottom surface of each heat exchanger plate 3 a. When unit elements 4 a and 4 b are alternately laminated, engagement projections 9 a and engagement recesses 10 b are engaged with each other, and engagement projections 9 b and engagement recesses 10 a are engaged with each other.

Heat exchanging element 1 a is a counter flow type in which primary and secondary airflows “A” and “B” flow at a right angle or an oblique angle to each other with heat exchanger plates 3 a therebetween in the vicinity of inlet ports 11 a, 11 b and outlet ports 12 a, 12 b, and flow opposite to each other with heat exchanger plates 3 a therebetween in the center. The regions in which primary and secondary airflows “A” and “B” flow opposite to each other with heat exchanger plates 3 a therebetween are referred to as counterflow regions 14 a. In counterflow regions 14 a, flow channels 13 a-13 f have a width of 18 mm.

Resin frames 2 a and 2 b are formed of a thermoplastic resin such as polystyrene (ABS, AS, or PS) or polyolefin (PP or PE). Heat exchanger plates 3 a are cut into a rectangular shape having a long side of 143 mm and a short side of 63 mm. The thickness is 0.2 to 0.01 mm, and preferably 0.1 to 0.01 mm. Heat exchanger plates 3 a can be made of Japanese paper, flame retardant paper, or specially-treated paper having heat conductivity, moisture permeability, and a gas shielding property, or can be a moisture-permeable film or a resin sheet or film having only heat conductivity such as polyester, polystyrene (ABS, AS, or PS), or polyolefin (PP or PE).

As shown in FIG. 3, the production process of heat exchanging element 1 a includes cutting step 15 a, molding step 16 a, laminating step 17 a, and bonding step 18 a performed in this order. Cutting step 15 a cuts heat exchanger plates 3 a into shape. Molding step 16 a integrally molds heat exchanger plate 3 a with resin frame 2 a so as to form unit element 4 a, and also integrally molds heat exchanger plate 3 a with resin frame 2 b so as to form unit element 4 b. Laminating step 17 a alternately laminates unit elements 4 a and unit elements 4 b on each other. Bonding step 18 a bonds unit elements 4 a and 4 b thus laminated.

Cutting step 15 a of the present embodiment cuts each heat exchanger plate 3 a into a rectangular shape having a long side of 143 mm and a short side of 63 mm.

Molding step 16 a inserts heat exchanger plate 3 a into an injection mold, injects molten resin into the mold, and solidifies the molten resin so as to form resin frames 2 a and 2 b. Resin frame 2 a is joined to heat exchanger plate 3 a, and resin frame 2 b is joined to heat exchanger plate 3 a so as to form unit elements 4 a and 4 b.

Laminating step 17 a laminates unit elements 4 a and unit elements 4 b alternately on each other so that engagement projections 9 a are engaged with engagement recesses 10 b, and engagement projections 9 b are engaged with engagement recesses 10 a.

Bonding step 18 a melts the four corners of unit elements 4 a and 4 b thus laminated, and parts of the edges of the regions where inlet ports 11 a, 11 b or outlet ports 12 a, 12 b are not formed. Bonding step 18 a then solidifies the molten resin so as to join unit elements 4 a and 4 b thus laminated. The resin can be melted by ultrasonic welding.

With the above structure, heat exchanging element 1 a allows primary and secondary airflows “A” and “B” to circulate through their corresponding air passages arranged alternately to prevent airflows “A” and “B” from being mixed with each other. Primary and secondary airflows “A” and “B” flow at a right angle or an oblique angle to each other with heat exchanger plates 3 a therebetween in the vicinity of inlet ports 11 a, 11 b and outlet ports 12 a, 12 b, and flow opposite to each other with heat exchanger plates 3 a therebetween in the center, that is, counterflow regions 14 a. Primary airflow “A” is drawn in from the short side and drawn out from a portion of the long side. Secondary airflow “B” is drawn in from the short side opposite to the side on which inlet ports 11 a of primary airflow “A” are formed, and is drawn out from a portion of the long side on which outlet ports 12 a of primary airflow “A” are formed. The rectangular picture plane of heat exchanging element 1 a in the lamination direction allows primary and secondary airflows “A” and “B” to flow opposite to each other in large counterflow regions 14 a with heat exchanger plates 3 a therebetween, thereby providing high heat exchange efficiency.

Shield portions 6 a, 6 b, flow channel division portions 7 a, 7 b, and rectification portions 8 a, 8 b play a role in maintaining both the spacing between heat exchanger plates 3 a and the strength of heat exchanging element 1 a, so that the spacing between heat exchanger plates 3 a can be kept uniform. This prevents drift due to uneven spacing between heat exchanger plates 3 a, which may be caused when the structural strength is low. As a result, high heat exchange efficiency can be provided while maintaining the structural strength.

Air passages 5A and 5B are divided into flow channels 13 a-13 c and 13 d-13 f, respectively, by flow channel division portions 7 a and 7 b so as to reduce the drift in air passages 5A and 5B. Flow channels 13 a-13 c and 13 d-13 f divided by flow channel division portions 7 a and 7 b, respectively, have different flow channel lengths, and hence, different ventilation resistances, thereby causing drift. The drift, however, is eliminated by providing rectification portions 8 a and 8 b in air passages 5A and 5B so as to change the ventilation resistances of flow channels 13 a-13 f. Furthermore, a predetermined flow velocity distribution is formed in counterflow regions 14 a so as to provide high heat exchange efficiency. The “predetermined flow velocity distribution” indicates approximately uniform flow velocities of flow channels 13 a-13 f in counterflow regions 14 a. However, the flow velocity distribution differs depending on the design condition of the heat exchange type ventilation fan, and is properly changed depending on the trade off between the size of heat exchanging element 1 a and the required ventilation resistance. Therefore, the flow velocity distribution may be designed so that the flow channel having the longest flow length has the highest velocity, instead of that all flow channels have approximately uniform velocities.

In air passages 5A and 5B, rectification portions 8 a and 8 b are located somewhere other than counterflow regions 14 a having the greatest effect on the heat exchange efficiency of heat exchanging element 1 a. This eliminates drift in air passages 5A and 5B due to different ventilation resistances of flow channels 13 a-13 f caused by their different flow channel lengths generated by flow channel division portions 7 a and 7 b, thereby forming a predetermined flow velocity distribution in counterflow regions 14 a. This results in providing high heat exchange efficiency.

Flow channels 13 a and 13 d having a flow channel length longer than the average flow channel length relatively have a large ventilation resistance and a low flow velocity. Flow channels 13 b, 13 c, 13 e, and 13 f having flow channel lengths shorter than the average flow channel length relatively have small ventilation resistances and high flow velocities. However, the provision of rectification portions 8 a and 8 b in inlet ports 11 a, 11 b and outlet ports 12 a, 12 b allows the opening area of inlet ports 11 a, 11 b and the opening area of outlet ports 12 a, 12 b of flow channels 13 a and 13 d having a flow channel length longer than the average flow channel length to be larger than the average opening area. This decreases the ventilation resistance of flow channels 13 a and 13 d, thereby increasing the flow velocity. The provision of rectification portions 8 a and 8 b also allows the opening area of inlet ports 11 a, 11 b and the opening area of outlet ports 12 a, 12 b of flow channels 13 b, 13 c, 13 e, and 13 f having flow channel lengths shorter than the average flow channel length to be made smaller than the average opening area. This increases the ventilation resistances of flow channels 13 b, 13 c, 13 e, and 13 f, thereby decreasing the flow velocities. Rectification portions 8 a and 8 b, which are formed by bending parts of flow channel division portions 7 a and 7 b, hardly decrease the effective area of heat exchanger plates 3 a or do not decrease the total opening area of inlet ports 11 a, 11 b or outlet ports 12 a, 12 b. This eliminate drift in air passages 5A and 5B due to different ventilation resistances of flow channels 13 a-13 f caused by their different lengths generated by flow channel division portions 7 a and 7 b so as to form a predetermined flow velocity distribution in counterflow regions 14 a. This results in providing high heat exchange efficiency.

Rectification portions 8 a and 8 b are arranged in inlet ports 11 a, 11 b and outlet ports 12 a, 12 b in the present embodiment. However, these portions 8 a and 8 b may alternatively be arranged in either inlet ports 11 a and 11 b or outlet ports 12 a and 12 b so as to obtain the same action and effect by changing the size of the opening areas.

As described above, heat exchanger plate 3 a is inserted into an injection mold for molding resin frames 2 a and 2 b, and molten resin is injected into the mold and solidified to form resin frames 2 a and 2 b. Resin frame 2 a is joined to heat exchanger plate 3 a, and resin frame 2 b is joined to heat exchanger plate 3 a. As a result, resin frames 2 a and 2 b are integrally molded with heat exchanger plates 3 a. This improves the joint strength between heat exchanger plate 3 a and resin frame 2 a having shield portions 6 a, flow channel division portions 7 a, and rectification portions 8 a, and also between heat exchanger plate 3 a and resin frame 2 b having shield portions 6 b, flow channel division portions 7 b, and rectification portions 8 b. As a result, this prevents airflow leakage due to peeling between heat exchanger plate 3 a and resin frames 2 a, 2 b.

The use of the injection molding process to integrally mold shield portions 6 a, flow channel division portions 7 a, and rectification portions 8 a and to integrally mold shield portions 6 b, flow channel division portions 7 b, rectification portions 8 b provides high-precision spacing between heat exchanger plates 3 a in the thickness direction. This enables heat exchanging element 1 a to maintain its strength, thus preventing bending of heat exchanger plates 3 a, which may be caused if the precision in the thickness direction is low while unit elements 4 a and 4 b are alternately laminated, and also preventing drift in air passages 5A and 5B which may be caused when unit elements 4 a and 4 b do not have a uniform height. This results in providing high heat exchange efficiency.

In the present embodiment, specific dimensions are given for resin frames 2 a and 2 b, heat exchanger plates 3 a, unit elements 4 a and 4 b, shield portions 6 a and 6 b, flow channel division portions 7 a and 7 b, rectification portions 8 a and 8 b, engagement projections 9 a and 9 b, engagement recesses 10 a and 10 b, inlet ports 11 a and 11 b, outlet ports 12 a and 12 b, and flow channels 13 a-13 f. These dimensions, however, are not limited to those of the present embodiment, and can be properly determined depending on the required performance of heat exchanging element 1 a so as to obtain the action and effect equivalent to those of the present embodiment.

Second Embodiment

FIG. 4 is a schematic perspective view of a heat exchanging element according to a second embodiment of the present invention. FIG. 5A is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 4. FIG. 5B is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction Y of FIG. 4. Like components are labeled with like reference numerals with respect to the first embodiment, and these components are not described again in detail.

As shown in FIGS. 4, 5A, and 5B, heat exchanging element 1 b according to the second embodiment includes unit elements 4 c and unit elements 4 d alternately laminated on each other. Each unit element 4 c includes heat exchanger plate 3 b integrally molded with resin frame 2 c. Each unit element 4 d includes heat exchanger plate 3 b integrally molded with resin frame 2 d. Each heat exchanger plate 3 b includes air passage 5C on its top surface and air passage 5D on its bottom surface. Heat exchanging element 1 b circulates primary airflow “A” through air passage 5C, and secondary airflow “B” through air passage 5D, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 b.

Unit elements 4 c are each formed by integrally molding heat exchanger plate 3 b with resin frame 2 c including shield portions 6 c, flow channel division portions 7 c, rectification portions 8 c, engagement projections 9 c, and engagement recesses 10 c. Unit elements 4 d are each formed by integrally molding heat exchanger plate 3 b with resin frame 2 d including shield portions 6 d, flow channel division portions 7 d, rectification portions 8 d, engagement projections 9 d, and engagement recesses 10 d.

Unit elements 4 c and 4 d have a picture plane with a long side of 145 mm and a short side of 65 mm in the lamination direction. The alternate lamination of unit elements 4 c and unit elements 4 d enables heat exchanging element 1 b to have inlet ports 11 c and outlet ports 12 c of primary airflow “A”, and inlet ports 11 d and outlet ports 12 d of secondary airflow “B”. Air passage 5C is divided into three flow channels 13 g, 13 h, and 13 i by flow channel division portions 7 c. Air passage 5D is divided into three flow channels 13 j, 13 k, and 13 m by flow channel division portions 7 d.

Shield portions 6 c and 6 d are arranged on the top and bottom surfaces, respectively of heat exchanger plate 3 b so as to form the outer frames excluding inlet ports 11 c, 11 d and outlet ports 12 c, 12 d. The linear portions of shield portions 6 c and 6 d have a width of 4 mm and a height of 0.75 mm. Flow channel division portions 7 c and 7 d, which have a width of 1.5 mm and a height of 0.75 mm are arranged on the top and bottom surfaces, respectively, of heat exchanger plate 3 b so as to fit each other when unit elements 4 a and 4 b are laminated.

Rectification portions 8 c are integrally formed with flow channel division portions 7 c in the vicinity of inlet ports 11 c, 11 d and outlet ports 12 c, 12 d so as to form projections projecting into flow channels 13 h, 13 i, 13 k, and 13 m. Some of the projections project 3 mm into flow channels 13 h, 13 k, and some of the projections project 5 mm into flow channels 13 i, 13 m from flow channel division portions 7 c.

The other projections are formed in counterflow regions 14 b in such a manner as to project 2 mm into flow channels 13 i, 13 m from shield portions 6 c.

Rectification portions 8 d are integrally formed with flow channel division portions 7 d in the vicinity of inlet ports 11 c, 11 d and outlet ports 12 c, 12 d so as to form projections projecting into flow channels 13 h, 13 i, 13 k, and 13 m. Some of the projections project 3 mm into flow channels 13 h, 13 k, and some of the projections project 5 mm into flow channels 13 i, 13 m from flow channel division portions 7 d.

The other projections are formed in counterflow regions 14 b in such a manner as to project 2 mm into flow channels 13 i, 13 m from shield portions 6 d. Rectification portions 8 c and 8 d fit each other when unit elements 4 c and 4 d are alternately laminated.

Rectification portions 8 c and 8 d are formed in the following conditions. The opening area of each of inlet and outlet ports 11 c, 12 c of flow channel 13 g and the opening area of each of inlet and outlet ports 11 d, 12 d of flow channel 13 j which have a flow channel length longer than the average flow channel length are made larger than the average opening area. The opening area of each of inlet and outlet ports 11 c, 12 c of flow channels 13 h, 13 i and the opening area of each of inlet and outlet ports 11 d, 12 d of flow channels 13 k, 13 m which have flow channel lengths shorter than the average flow channel length are made smaller than the average opening area.

The flow channel lengths in the present embodiments are as follows: flow channels 13 g and 13 j: 174 mm; flow channels 13 h and 13 k: 136 mm; and flow channels 13 i and 13 m: 104 mm. The average flow channel length is 138 mm. The opening areas in the present embodiment are as follows: inlet and outlet ports 11 c, 12 c of flow channel 13 g and inlet and outlet ports 11 d, 12 d of flow channel 13 j: 27 mm²; inlet and outlet ports 11 c, 12 c of flow channel 13 h and inlet and outlet ports 11 d, 12 d of flow channel 13 k: 16.5 mm²; and inlet and outlet ports 11 c, 12 c of flow channel 13 i and inlet and outlet ports 11 d, 12 d of flow channel 13 m: 12 mm². The total opening area of inlet ports 11 c, 11 d and the total opening area of outlet ports 12 c, 12 d are both 55.5 mm². The average opening area of inlet ports 11 c, 11 d and the average opening area of outlet ports 12 c, 12 d are both 18.5 mm².

Engagement projections 9 c and 9 d, which have a width of 1.5 mm and a height of 0.4 mm, are arranged on shield portions 6 c and 6 d, respectively formed on the top surface of each heat exchanger plate 3 b. Engagement recesses 10 c and 10 d, which have a width of 1.6 mm and a depth of 0.5 mm, are arranged on shield portions 6 c and 6 d, respectively formed on the bottom surface of each heat exchanger plate 3 b. When unit elements 4 c and 4 d are alternately laminated, engagement projections 9 c and engagement recesses 10 d are engaged with each other, and engagement projections 9 d and engagement recesses 10 c are engaged with each other.

Heat exchanging element 1 b is a counter flow type in which primary and secondary airflows “A” and “B” flow at a right angle or an oblique angle to each other with heat exchanger plates 3 b therebetween in the vicinity of inlet ports 11 c, 11 d and outlet ports 12 c, 12 d, and flow opposite to each other with heat exchanger plates 3 b therebetween in the center. The regions in which primary and secondary airflows “A” and “B” flow opposite to each other with heat exchanger plates 3 b therebetween are counterflow regions 14 b. In counterflow regions 14 b, flow channels 13 g, 13 h, 13 i, 13 j, 13 k, and 13 m, which are divided by shield portions 6 c, 6 d and flow channel division portions 7 c, 7 d, have a width of 18 mm.

Resin frames 2 c and 2 d are formed of a thermoplastic resin such as polystyrene (ABS, AS, or PS), or polyolefin (PP or PE). Heat exchanger plates 3 b are cut into a rectangular shape having a long side of 143 mm and a short side of 63 mm. The thickness is 0.2 to 0.01 mm, and preferably 0.1 to 0.01 mm. Heat exchanger plates 3 b can be made of Japanese paper, flame retardant paper, or specially-treated paper having heat conductivity, moisture permeability, and a gas shielding property, or can be a moisture-permeable film or a resin sheet or film having only heat conductivity such as polyester, polystyrene (ABS, AS, or PS) or polyolefin (PP or PE).

Heat exchanging element 1 b according to the present embodiment has the same production process as heat exchanging element 1 a of the first embodiment, and it is described with reference to FIG. 3. The production process of heat exchanging element 1 b includes cutting step 15 a, molding step 16 a, laminating step 17 a, and bonding step 18 a performed in this order. Cutting step 15 a cuts heat exchanger plates 3 b into shape. Molding step 16 a integrally molds heat exchanger plate 3 b with resin frame 2 c so as to form unit element 4 c, and also integrally molds heat exchanger plate 3 b with resin frame 2 d so as to form unit element 4 d. Laminating step 17 a alternately laminates unit elements 4 c and unit elements 4 d on each other. Bonding step 18 a bonds laminated unit elements 4 c and 4 d.

Cutting step 15 a of the present embodiment cuts each heat exchanger plate 3 b into a rectangular shape having a long side of 143 mm and a short side of 63 mm.

Molding step 16 a inserts heat exchanger plate 3 b into an injection mold, injects molten resin into the mold, and solidifies the molten resin so as to form resin frames 2 c and 2 d. Resin frame 2 c is joined to heat exchanger plate 3 b, and resin frame 2 d is joined to heat exchanger plate 3 b so as to form unit elements 4 c and 4 d.

Laminating step 17 a laminates unit elements 4 c and unit elements 4 d alternately on each other so that engagement projections 9 c are engaged with engagement recesses 10 d, and engagement projections 9 d are engaged with engagement recesses 10 c.

Bonding step 18 a melts the four corners of unit elements 4 c and 4 d thus laminated, and parts of the edges of the regions where inlet ports 11 c, 11 d or outlet ports 12 c, 12 d are not formed. Bonding step 18 a then solidifies the molten resin so as to join unit elements 4 c and 4 d thus laminated. The resin can be melted by ultrasonic welding.

With the above structure, heat exchanging element 1 b allows primary and secondary airflows “A” and “B” to circulate through their corresponding air passages arranged alternately to prevent airflows “A” and “B” from being mixed with each other, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 b.

Besides rectification portions 8 c and 8 d, like components are labeled with like reference numerals with respect to the first embodiment, and these components are not described again in detail.

Air passage 5C includes flow channels 13 g, 13 h, and 13 i, and flow channel 13 g has the longest flow channel length. Air passage 5D includes flow channels 13 j, 13 k, and 13 m, and flow channel 13 j has the longest flow channel length. Flow channels 13 g and 13 j having the longest flow channel length have a higher ventilation resistance than the other flow channels 13 h, 13 i, 13 k, and 13 m. To increase the ventilation resistances of flow channels 13 h, 13 i, 13 k, and 13 m, flow channel division portions 7 c and 7 d are provided with projections as ventilation resistance members projecting into flow channels 13 h, 13 i, 13 k, and 13 m in inlet and outlet ports 11 c, 12 c of flow channels 13 h, 13 i and in inlet and outlet ports 11 d, 12 d of flow channels 13 k, 13 m. These projections function as rectification portions 8 c and 8 d to reduce the opening area of each of inlet and outlet ports 11 c, 12 c of flow channels 13 h, 13 i and the opening area of each of inlet and outlet ports 11 d, 12 d of flow channels 13 k, 13 m including rectification portions 8 c and 8 d, thereby increasing the ventilation resistances. This eliminates drift in air passages 5C and 5D due to different ventilation resistances of flow channels 13 g, 13 h, 13 i, 13 j, 13 k, and 13 m caused by their different flow channel lengths generated by flow channel division portions 7 c and 7 d, thereby forming a predetermined flow velocity distribution in counterflow regions 14 b. This results in providing high heat exchange efficiency.

Furthermore, (not illustrated) arranging some of rectification portions 8 c and 8 d as the projections in counterflow regions 14 d eliminates drift in flow channels 13 i and 13 m and increases the ventilation resistances of flow channels 13 i and 13 m. This eliminates drift in air passages 5C and 5D due to different ventilation resistances of flow channels 13 g, 13 h, 13 i, 13 j, 13 k, and 13 m caused by their different flow channel lengths generated by flow channel division portions 7 c and 7 d. This results in providing high heat exchange efficiency.

Rectification portions 8 c and 8 d are arranged in inlet ports 11 c, 11 d, outlet ports 12 c, 12 d, and counterflow regions 14 b in the present embodiment. However, these portions 8 c and 8 d may alternatively be arranged in either inlet ports 11 c and 11 d or outlet ports 12 c and 12 d and counterflow regions 14 b, or in either inlet ports 11 c and 11 d or outlet ports 12 c and 12 d so as to obtain the same action and effect by changing the size of the opening areas.

In the present embodiment, specific dimensions are given for resin frames 2 c and 2 d, heat exchanger plates 3 b, unit elements 4 c and 4 d, shield portions 6 c and 6 d, flow channel division portions 7 c and 7 d, rectification portions 8 c and 8 d, engagement projections 9 c and 9 d, engagement recesses 10 c and 10 d, inlet ports 11 c and 11 d, outlet ports 12 c and 12 d, and flow channels 13 g, 13 h, 13 i, 13 j, 13 k, and 13 m. These dimensions, however, are not limited to those of the present embodiment, and can be properly determined depending on the required performance of heat exchanging element 1 b so as to obtain the action and effect equivalent to those of the present embodiment.

Third Embodiment

FIG. 6 is a schematic perspective view of a heat exchanging element according to a third embodiment of the present invention. FIG. 7 is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 6. FIG. 8 is a schematic production flowchart of the heat exchanging element. Like components are labeled with like reference numerals with respect to the first and second embodiments, and these components are not described again in detail.

As shown in FIGS. 6 and 7, heat exchanging element 1 c includes unit elements 4 e and unit elements 4 f alternately laminated on each other. Each unit element 4 e includes shield portions 6 e, flow channel division portions 7 e, rectification portions 8 e, and spaced projections 19 a, which are formed by providing an uneven surface structure on heat exchanger plate 3 c. Each unit element 4 f includes shield portions 6 f, flow channel division portions 7 f, rectification portions 8 f, and spaced projections 19 b, which are formed by providing an uneven surface structure on heat exchanger plate 3 c. Each heat exchanger plate 3 c includes air passage 5E on its top surface and air passage 5F on its bottom surface. Heat exchanging element 1 c circulates primary airflow “A” through air passage 5E, and secondary airflow “B” through air passage 5F, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 c.

Unit elements 4 e and 4 f have a picture plane having a long side of 145 mm and a short side of 65 mm in the lamination direction after bonded. Unit elements 4 e and 4 f are formed by vacuum forming a polystyrene sheet having a thickness of, for example, 0.2 mm.

The alternate lamination of unit elements 4 e and unit elements 4 f enables heat exchanging element 1 c to have inlet ports 11 e and outlet ports 12 e of primary airflow “A” and inlet ports 11 f and outlet ports 12 f of secondary airflow “B”. Air passage 5E is divided into three flow channels 13 n, 13 p, and 13 q by flow channel division portions 7 e. Air passage 5F is divided into three flow channels 13 r, 13 s, and 13 t.

Shield portions 6 e and 6 f are arranged to form the outer frames excluding inlet ports 11 e, 11 f and outlet port 12 e, 12 f. The linear portions of shield portions 6 e and 6 f have a width of 4 mm and a height of 1.5 mm from heat exchanger plate 3 c.

Flow channel division portions 7 e and 7 f are arranged to have a width of 1.5 mm and a height of 1.5 mm from heat exchanger plate 3 c.

Rectification portions 8 e are integrally formed with flow channel division portions 7 e by bending flow channel division portions 7 e in the vicinity of inlet and outlet ports 11 e, 12 e so as to have a width of 1.5 mm and a height of 1.5 mm from heat exchanger plate 3 c. Rectification portions 8 f are integrally formed with flow channel division portions 7 f by bending flow channel division portions 7 f in the vicinity of inlet and outlet ports 11 f, 12 f so as to have a width of 1.5 mm and a height of 1.5 mm from heat exchanger plate 3 c.

Rectification portions 8 e and 8 f are formed by bending flow channel division portions 7 e and 7 f in the following conditions. The opening area of each of inlet and outlet ports 11 e, 12 e of flow channel 13 n and the opening area of each of inlet and outlet ports 11 f, 12 f of flow channel 13 r which have a flow channel length longer than the average flow channel length are made larger than the average opening area. The opening area of each of inlet and outlet ports 11 e, 12 e of flow channels 13 p, 13 q and the opening area of each of inlet and outlet ports 11 f, 12 f of flow channels 13 s, 13 t which have flow channel lengths shorter than the average flow channel length are made smaller than the average opening area.

The flow channel lengths in the present embodiment are as follows: flow channels 13 n and 13 r: 182 mm; flow channels 13 p and 13 s: 142 mm; and flow channels 13 q and 13 t: 105 mm. The average flow channel length is 143 mm. The opening areas in the present invention are as follows: inlet ports 11 e and 11 f respectively of flow channels 13 n and 13 r: 39 mm²; outlet ports 12 e and 12 f respectively of flow channels 13 n and 13 r: 34.5 mm²; inlet ports 11 e and 11 f respectively of flow channels 13 p and 13 s: 22.5 mm²; outlet ports 12 e and 12 f respectively of flow channel 13 p and 13 s: 24 mm²; inlet ports 11 e and 11 f respectively of flow channels 13 q and 13 t: 15 mm², and outlet ports 12 e and 12 f respectively of flow channels 13 q and 13 t: 18 mm². The total opening area of inlet ports 11 e, 11 f and the total opening area of outlet ports 12 e, 12 f are both 76.5 mm². The average opening area of inlet ports 11 e, 11 f and the average opening area of outlet port 12 e, 12 f are both 25.5 mm².

Spaced projections 19 a, 19 b, which are arranged on shield portions 6 e, 6 f, flow channel division portions 7 e, 7 f, and rectification portions 8 e, 8 f, respectively, play a role in maintaining the spacing between heat exchanger plates 3 c when unit elements 4 e and 4 f are alternately laminated.

Heat exchanging element 1 c is a counter flow type in which primary and secondary airflows “A” and “B” flow at a right angle or an oblique angle to each other with heat exchanger plates 3 c therebetween in the vicinity of inlet ports 11 e, 11 f and outlet ports 12 e, 12 f, and flow opposite to each other with heat exchanger plates 3 c therebetween in the center. The regions in which primary and secondary airflows “A” and “B” flow opposite to each other with heat exchanger plates 3 c therebetween are referred to as counterflow regions 14 c. In counterflow regions 14 c, flow channels 13 n, 13 p, 13 q, 13 r, 13 s, and 13 t have a width of 18 mm.

Heat exchanger plates 3 c are formed of resin sheets or films of polyester, polystyrene (ABS, AS, or PS), or polyolefin (PP or PE). The thickness is preferably 0.2 to 0.1 mm, and is 0.2 mm in the present embodiment.

As shown in FIG. 8, the production process of heat exchanging element 1 c includes cutting step 15 b, molding step 16 b, laminating step 17 b, and bonding step 18 b performed in this order. Cutting step 15 b cuts heat exchanger plates 3 c into shape. Molding step 16 b forms an uneven surface structure on heat exchanger plates 3 c by a forming method such as vacuum forming, and then cuts unnecessary parts off so as to form unit elements 4 e and 4 f. Laminating step 17 b alternately laminates unit elements 4 e and unit elements 4 f on each other. Bonding step 18 b bonds unit elements 4 e and 4 f thus laminated.

Molding step 16 b forms the uneven surface structure by processing heat exchanger plate 3 c of a polystyrene sheet or the like by vacuum forming, and cuts off parts unnecessary to form heat exchanging element 1 c so as to form unit elements 4 e and 4 f. Besides vacuum forming, heat exchanger plate 3 c may be formed by air-pressure forming, pressing or the like.

Bonding step 18 b melts the edges of laminated unit elements 4 e and 4 f, and solidifies the molten resin so as to join unit elements 4 e and 4 f thus laminated.

With the above structure, heat exchanging element 1 c allows primary and secondary airflows “A” and “B” to circulate through their corresponding air passages arranged alternately to prevent airflows “A” and “B” from being mixed with each other, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 c.

Like components are labeled with like reference numerals with respect to the first embodiment, and these components are not described again in detail.

Unit elements 4 e and 4 f are formed by providing the uneven surface structure on heat exchanger plates 3 c, which are formed of a thermoplastic resin such as polystyrene by vacuum forming or the like. Heat exchanger plates 3 c, shield portions 6 e, 6 f, flow channel division portions 7 e, 7 f, rectification portions 8 e, 8 f, and spaced projections 19 a, 19 b are all made of the same material. This prevents peeling between heat exchanger plates 3 c and other components, and hence, airflow leakage due to peeling. The integral molding of shield portions 6 e, flow channel division portions 7 e, rectification portions 8 e, and spaced projections 19 a; and the integral molding of shield portions 6 f, flow channel division portions 7 f, rectification portions 8 f, and spaced projections 19 b provide high-precision spacing between heat exchanger plates 3 c in the thickness direction when unit elements 4 e and 4 f are laminated on each other. This enables the heat exchanging element to maintain its strength, thus preventing bending of heat exchanger plates 3 c, which may be caused if the precision in the thickness direction is low while unit elements 4 e and 4 f are alternately laminated, and also preventing drift in air passages 5E and 5F which may be caused when unit elements 4 e and 4 f do not have a uniform height. This results in providing high heat exchange efficiency.

In the present embodiment, specific dimensions are given for heat exchanger plates 3 c, unit elements 4 e and 4 f, shield portions 6 e and 6 f, flow channel division portions 7 e and 7 f, rectification portions 8 e and 8 f, inlet ports 11 e and 11 f, outlet ports 12 e and 12 f, flow channels 13 n, 13 p, 13 q, 13 r, 13 s, and 13 t, and spaced projections 19 a and 19 b. These dimensions, however, are not limited to those of the present embodiment, and can be properly determined depending on the required performance of heat exchanging element 1 c so as to obtain the action and effect equivalent to those of the present embodiment.

Fourth Embodiment

FIG. 9 is a schematic perspective view of a heat exchanging element according to a fourth embodiment of the present invention. FIG. 10A is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction X of FIG. 9. FIG. 10B is an enlarged schematic perspective view of one unit element as a component of the heat exchanging element seen in the direction X of FIG. 9. FIG. 10C is an enlarged schematic perspective view of the unit element taken along line A-A of FIG. 10B. FIG. 11 is a schematic perspective view of one unit element as a component of the heat exchanging element seen in a direction Y of FIG. 9. Like components are labeled with like reference numerals with respect to the first to third embodiments, and these components are not described again in detail.

As shown in FIGS. 9, 10A, 10B, 10C, and 11, heat exchanging element 1 d includes unit elements 4 g and unit elements 4 h alternately laminated on each other. Each unit element 4 g includes heat exchanger plate 3 d integrally molded with resin frame 2 e. Each unit element 4 h includes heat exchanger plate 3 d integrally molded with resin frame 2 f. Each heat exchanger plate 3 d includes air passage 5G on its top surface and air passage 5H on its bottom surface. Heat exchanging element 1 d circulates primary airflow “A” through air passage 5G, and secondary airflow “B” through air passage 5H, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 d.

Unit elements 4 g are each formed by integrally molding heat exchanger plate 3 d with resin frame 2 e including shield portions 6 g, flow channel division portions 7 g, rectification portions 8 g, engagement projections 9 e, and engagement recesses 10 e. Unit elements 4 h are each formed by integrally molding heat exchanger plate 3 d with resin frame 2 f including shield portions 6 h, flow channel division portions 7 h, rectification portions 8 h, engagement projections 9 f, and engagement recesses 10 f. Unit elements 4 g and 4 h have a picture plane having a long side of 145 mm and a short side of 65 mm in the lamination direction.

The alternate lamination of unit elements 4 g and unit elements 4 h enables heat exchanging element 1 d to have inlet ports 11 g and outlet ports 12 g of primary airflow “A” and inlet ports 11 h and outlet ports 12 h of secondary airflow “B”. Air passage 5G is divided into three flow channels 13 u, 13 v, and 13 w by flow channel division portions 7 g. Air passage 5H is divided into three flow channels 13 x, 13 y, and 13 z by flow channel division portions 7 h.

Shield portions 6 g and 6 h are arranged on the top and bottom surfaces, respectively, of heat exchanger plate 3 d so as to form the outer frames excluding inlet ports 11 g, 11 h and outlet ports 12 g, 12 h. The linear portions of shield portions 6 g and 6 h have a width of 4 mm and a height of 0.75 mm.

Flow channel division portions 7 g and 7 h, which have a width of 1.5 mm and a height of 0.75 mm, are arranged on the top and bottom surfaces, respectively, of heat exchanger plate 3 d so as to fit each other when unit elements 4 g and 4 h are laminated. Rectification portions 8 g include portions that are integrated with shield portions 6 g in the vicinity of inlet ports 11 g, 11 h and outlet ports 12 g, 12 h, and portions that are formed between one side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 g.

Of rectification portions 8 g, the portions that are integrated with shield portions 6 g in the vicinity of inlet ports 11 g, 11 h and outlet ports 12 g, 12 h form projections projecting into flow channels 13 v, 13 w, 13 y, and 13 z. The projections projecting into flow channels 13 v and 13 y are inclined with respect to shield portions 6 g by 0.3 mm on the opening side and by 0 mm on the inner side. The projections projecting into flow channels 13 w and 13 z are inclined with respect to shield portions 6 g by 0.15 mm on the opening side and by 0 mm on the inner side.

Of rectification portions 8 g, the portions that are formed between the flow-channel (13 v, 13 w, 13 y, or 13 z) side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 g form projections projecting 0.15 mm. The “opening side” indicates the side of inlet port 11 g or 11 h or the side of outlet ports 12 g or 12 h as seen from inside heat exchanging element 1 d. The “inner side” indicates inside heat exchanging element 1 d as seen from inlet port 11 g or 11 h or outlet ports 12 g and 12 h.

Rectification portions 8 h include portions that are integrated with shield portions 6 h in the vicinity of inlet ports 11 g, 11 h and outlet ports 12 g, 12 h, and portions that are formed between one side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 h. Of rectification portions 8 h, the portions that are integrated with shield portions 6 h in the vicinity of inlet ports 11 g, 11 h and outlet ports 12 g, 12 h form projections projecting into flow channels 13 v, 13 w, 13 y, and 13 z. The projections projecting into flow channels 13 v and 13 y are inclined with respect to shield portions 6 h by 0.3 mm on the opening side and by 0 mm on the inner side. The projections projecting into flow channels 13 w and 13 z are inclined with respect to shield portions 6 h by 0.15 mm on the opening side and by 0 mm on the inner side. Of rectification portions 8 h, the portions that are formed between the flow-channel (13 v, 13 w, 13 y, or 13 z) side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 h form projections projecting 0.15 mm.

Rectification portions 8 g and 8 h are formed in the following conditions. The opening area of each of inlet and outlet ports 11 g, 12 g of flow channels 13 v, 13 w and the opening area of each of inlet and outlet ports 11 h, 12 h of flow channels 13 y, 13 z are made smaller than the opening area of each of inlet and outlet ports 11 g, 12 g of flow channel 13 u and the opening area of each of inlet and outlet ports 11 h, 12 h of flow channel 13 x which have the longest flow channel length. The flow channel lengths in the present embodiment are as follows: flow channels 13 u and 13 x: 180 mm; flow channels 13 v and 13 y: 140 mm; and flow channels 13 w and 13 z: 104 mm. The average flow channel length is 141.3 mm. The opening areas in the present embodiment are as follows: inlet and outlet ports 11 g, 12 g of flow channel 13 u and inlet and outlet ports 11 h, 12 h of flow channel 13 x: 27 mm²; inlet and outlet ports 11 g, 12 g of flow channel 13 v and inlet and outlet ports 11 h, 12 h of flow channel 13 y: 21.6 mm²; and inlet and outlet ports 11 g, 12 g of flow channel 13 w and inlet and outlet ports 11 h, 12 h of flow channel 13 z: 16.2 mm².

Engagement projections 9 e and 9 f, which have a width of 1.5 mm and a height of 0.4 mm, are arranged on shield portions 6 g and 6 h, respectively formed on the top surface of each heat exchanger plate 3 d. Engagement recesses 10 e and 10 f, which have a width of 1.6 mm and a depth of 0.5 mm, are arranged on shield portions 6 g and 6 h, respectively formed on the bottom surface of each heat exchanger plate 3 d. When unit elements 4 g and 4 h are alternately laminated, engagement projections 9 e and engagement recesses 10 f are engaged with each other, and engagement projections 9 f and engagement recesses 10 e are engaged with each other.

Heat exchanging element 1 d is a counter flow type in which primary and secondary airflows “A” and “B” flow at a right angle or an oblique angle to each other with heat exchanger plates 3 d therebetween in the vicinity of inlet ports 11 g, 11 h and outlet ports 12 g, 12 h, and flow opposite to each other with heat exchanger plates 3 d therebetween in the center. The regions in which primary and secondary airflows “A” and “B” flow opposite to each other with heat exchanger plates 3 d therebetween are referred to as counterflow regions 14 d. In counterflow regions 14 d, flow channels 13 u, 13 v, 13 w, 13 x, 13 y, and 13 z, which are divided by shield portions 6 g, 6 h and flow channel division portions 7 g, 7 h, have a width of 18 mm.

Resin frames 2 e and 2 f are formed of a thermoplastic resin such as polystyrene (ABS, AS, or PS) or polyolefin (PP or PE). Heat exchanger plates 3 d are cut into a rectangular shape having a long side of 143 mm and a short side of 63 mm. The thickness is 0.2 to 0.01 mm, and preferably 0.1 to 0.01 mm. Heat exchanger plates 3 d can be made of Japanese paper, flame retardant paper, or specially-treated paper having heat conductivity, moisture permeability, and a gas shielding property, or can be a moisture-permeable film or a resin sheet or film having only heat conductivity such as polyester, polystyrene (ABS, AS, or PS), or polyolefin (PP or PE).

Heat exchanging element 1 d according to the present embodiment has the same production process as heat exchanging element 1 a of the first embodiment, and it is described with reference to FIG. 3. The production process of heat exchanging element 1 d includes cutting step 15 a, molding step 16 a, laminating step 17 a, and bonding step 18 a performed in this order. Cutting step 15 a cuts heat exchanger plates 3 d into shape. Molding step 16 a integrally molds heat exchanger plate 3 d with resin frame 2 e so as to form unit element 4 g, and also integrally molds heat exchanger plate 3 d with resin frame 2 f so as to form unit element 4 h. Laminating step 17 a alternately laminates unit elements 4 g and unit elements 4 h on each other. Bonding step 18 a bonds laminated unit elements 4 g and 4 h.

Cutting step 15 a of the present embodiment cuts each heat exchanger plate 3 d into a rectangular shape having a long side of 143 mm and a short side of 63 mm.

Molding step 16 a inserts heat exchanger plate 3 d into an injection mold, injects molten resin into the mold, and solidifies the molten resin so as to form resin frames 2 e and 2 f. Resin frame 2 e is joined to heat exchanger plate 3 d, and resin frame 2 f is joined to heat exchanger plate 3 d so as to form unit elements 4 g and 4 h.

Laminating step 17 a laminates unit elements 4 g and unit elements 4 h alternately on each other so that engagement projections 9 e are engaged with engagement recesses 10 f, and engagement projections 9 f are engaged with engagement recesses 10 e.

Bonding step 18 a melts the four corners of unit elements 4 g and 4 h thus laminated, and parts of the edges of the regions where inlet ports 11 g, 11 h or outlet ports 12 g, 12 h are not formed. Bonding step 18 a then solidifies the molten resin so as to join unit elements 4 g and 4 h thus laminated. The resin can be melted by ultrasonic welding.

With the above structure, heat exchanging element 1 d allows primary and secondary airflows “A” and “B” to circulate through their corresponding air passages arranged alternately to prevent airflows “A” and “B” from being mixed with each other, thereby enabling heat exchange between primary and secondary airflows “A” and “B” via heat exchanger plates 3 d.

Besides rectification portions 8 g and 8 h, like components are labeled with like reference numerals with respect to the first embodiment, and these components are not described again in detail.

Air passage 5G includes flow channels 13 u, 13 v, and 13 w, and flow channel 13 u has the longest flow channel length. Air passage 5H includes flow channels 13 x, 13 y, and 13 z, and flow channel 13 x has the longest flow channel length. If rectification portions 8 g and 8 h are not provided, flow channels 13 u and 13 x having the longest flow channel length have a higher ventilation resistance than the other flow channels 13 v, 13 w, 13 y, and 13 z. To increase the ventilation resistances of flow channels 13 v, 13 w, 13 y, and 13 z, shield portions 6 g and 6 h are provided with projections as ventilation resistance members projecting into flow channels 13 v, 13 w, 13 y, and 13 z in inlet and outlet ports 11 g, 12 g of flow channels 13 v, 13 w and in inlet and outlet ports 11 h, 12 h of flow channels 13 y, 13 z. These projections function as rectification portions 8 g and 8 h to reduce the opening area of each of inlet and outlet ports 11 g, 12 g of flow channels 13 v, 13 w and the opening area of each of inlet and outlet ports 11 h, 12 h of flow channels 13 y, 13 z including rectification portions 8 g and 8 h, thereby increasing the ventilation resistances.

This eliminates drift in air passages 5G and 5H due to different ventilation resistances of flow channels 13 u, 13 v, 13 w, 13 x, 13 y, and 13 z caused by their different flow channel lengths generated by flow channel division portions 7 g and 7 h, thereby forming a predetermined flow velocity distribution in counterflow regions 14 d. This results in providing high heat exchange efficiency. As described above, the portions that are formed between the flow-channel (13 v, 13 w, 13 y, or 13 z) side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 g, 7 h form projections as ventilation resistance members, which function as rectification portions 8 g, 8 h. This increases the ventilation resistances of flow channels 13 v, 13 w, 13 y, and 13 z including rectification portions 8 g and 8 h. As a result, this eliminates drift in air passages 5G and 5H due to different ventilation resistances of flow channels 13 u, 13 v, 13 w, 13 x, 13 y, and 13 z caused by their different flow channel lengths generated by flow channel division portions 7 g and 7 h, thereby forming a predetermined flow velocity distribution in counterflow regions 14 d. This results in providing high heat exchange efficiency. Rectification portions 8 g and 8 h are arranged in inlet ports 11 g and 11 h, outlet ports 12 g and 12 h, and in some portions between one side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 g or 7 h in the present embodiment. However, these portions 8 g and 8 h may alternatively be arranged in either inlet ports 11 g and 11 h or outlet ports 12 g and 12 h, and in some portions between one side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 g or 7 h; only in inlet ports 11 g, 11 h and outlet port 12 g, 12 h; or only in some portions between one side surface of heat exchanger plate 3 d and the reverse side of flow channel division portions 7 g or 7 h. In all of these cases, the same action and effect can be obtained by changing the size of the opening areas.

In the present embodiment, specific dimensions are given for resin frames 2 e and 2 f, heat exchanger plates 3 d, unit elements 4 g and 4 h, shield portions 6 g and 6 h, flow channel division portions 7 g and 7 h, rectification portions 8 g and 8 h, engagement projections 9 e and 9 f, engagement recesses 10 e and 10 f, inlet ports 11 g and 11 h, outlet ports 12 g and 12 h, and flow channels 13 u, 13 v, 13 w, 13 x, 13 y, and 13 z. These dimensions, however, are not limited to those of the present embodiment, and can be properly determined depending on the required performance of heat exchanging element 1 d so as to obtain the action and effect equivalent to those of the present embodiment.

INDUSTRIAL APPLICABILITY

The lamination type heat exchanging element of the present invention, which is for use in heat exchange type ventilation fans for domestic use, in heat exchange type ventilators for buildings or other structures, and in other air conditioning devices, provides high industrial applicability. 

1. A heat exchanging element for performing heat exchange by circulating a primary airflow and a secondary airflow through corresponding air passages alternately formed between a plurality of heat exchanger plates laminated on each other with a predetermined spacing, the heat exchanging element comprising: counterflow regions in which the primary airflow and the secondary airflow flow opposite to each other with the heat exchanger plates therebetween; shield portions for preventing airflow leakage from regions other than inlet ports and outlet ports of the primary airflow and the secondary airflow in the air passages; flow channel division portions for dividing each of the air passages into a plurality of flow channels, the flow channels divided by the flow channel division portions having different flow channel lengths from each other; and rectification portions arranged in the air passages, the rectification portions providing a predetermined flow velocity distribution of the primary airflow and the secondary airflow circulating through the counterflow regions in the flow channels divided by the flow channel division portions.
 2. The heat exchanging element of claim 1, wherein the rectification portions are located in the air passages other than the counterflow regions.
 3. The heat exchanging element of claim 1, wherein the rectification portions are ventilation resistance members shaped to increase ventilation resistances of flow channels other than the longest flow channel having the longest flow channel length of all the flow channels divided by the flow channel division portions.
 4. The heat exchanging element of claim 3, wherein the rectification portions are partially or wholly located in inlet ports of the flow channels other than the longest flow channel so that an opening area of each of the inlet ports of the flow channels other than the longest flow channel can be smaller than an opening area of an inlet port of the longest flow channel.
 5. The heat exchanging element of claim 3, wherein the rectification portions are partially or wholly located in outlet ports of the flow channels other than the longest flow channel so that an opening area of each of the outlet ports of the flow channels other than the longest flow channel can be smaller than an opening area of an outlet port of the longest flow channel.
 6. The heat exchanging element of claim 3, wherein the rectification portions are partially or wholly located in inlet ports and outlet ports of the flow channels other than the longest flow channel so that an opening area of each of the inlet ports and an opening area of each of the outlet ports of the flow channels other than the longest flow channel can be smaller than an opening area of an inlet port and an opening area of an outlet port, respectively, of the longest flow channel.
 7. The heat exchanging element of claim 1, wherein the rectification portions are shaped to decrease ventilation resistances of flow channels having flow channel lengths longer than an average flow channel length of the flow channels divided by the flow channel division portions and to increase ventilation resistances of flow channels having flow channel lengths shorter than the average flow channel length.
 8. The heat exchanging element of claim 7, wherein the rectification portions are partially or wholly located in the inlet ports of the flow channels so that an opening area of each of the inlet ports of the flow channels having longer flow channel lengths than the average flow channel length can be larger than an average opening area of the inlet ports, and that an opening area of each of the inlet ports of the flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area of the inlet ports.
 9. The heat exchanging element of claim 7, wherein the rectification portions are partially or wholly located in the outlet ports of the flow channels so that an opening area of each of the outlet ports of the flow channels having longer flow channel lengths than the average flow channel length can be larger than an average opening area of the outlet ports, and that an opening area of each of the outlet ports of the flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area of the outlet ports.
 10. The heat exchanging element of claim 7, wherein the rectification portions are partially or wholly located in the inlet ports and the outlet ports of the flow channels so that an opening area of each of the inlet ports and an opening area of each of the outlet ports of the flow channels having longer flow channel lengths than the average flow channel length can be larger than an average opening area of the inlet ports and an average opening area of the outlet ports, respectively, and that an opening area of each of the inlet ports and an opening area of each of the outlet ports of the flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area of the inlet ports and the average opening area of the outlet ports, respectively.
 11. The heat exchanging element of claim 1, wherein the flow channel division portions are partially integrated with the rectification portions, and the rectification portions are formed by bending parts of the flow channel division portions in such a manner that an opening area of flow channels having longer flow channel lengths than an average flow channel length of the flow channels divided by the flow channel division portions can be larger than an average opening area, and that an opening area of flow channels having shorter flow channel lengths than the average flow channel length can be smaller than the average opening area.
 12. The heat exchanging element of claim 1, wherein the rectification portions that increase ventilation resistances of the flow channels divided by the flow channel division portions are integrally formed with the flow channel division portions, the rectification portions being formed as projections on surfaces of the flow channel division portions that are in contact with the flow channels.
 13. The heat exchanging element of claim 1, wherein the rectification portions that increase ventilation resistances of the flow channels divided by the flow channel division portions are integrally formed with the shield portions, the rectification portions being formed as projections on some or all surfaces of the shield portions that are in contact with opening sections of the flow channels.
 14. The heat exchanging element of claim 12, wherein the projections are high on an opening side and low on an inner side.
 15. The heat exchanging element of claim 1, wherein the rectification portions that increase ventilation resistances of the flow channels divided by the flow channel division portions are formed as projections on the heat exchanger plates.
 16. The heat exchanging element of claim 15, wherein the projections are formed between one side surface of the heat exchanger plates and a reverse side of the flow channel division portions.
 17. The heat exchanging element of claim 1, wherein the heat exchanger plates are integrally molded with resin frames using an injection molding process so as to form a plurality of unit elements, the heat exchanger plates being made of paper or resin and having heat conductivity, moisture permeability, and a gas shielding property, the resin frames being made of synthetic resin and forming the air passages including the shield portions, the flow channel division portions, and the rectification portions, and the plurality of unit elements being laminated on each other.
 18. The heat exchanging element of claim 1, wherein the heat exchanger plates made of thermoplastic resin are each provided with an uneven surface structure so as to form the shield portions, the flow channel division portions, and the rectification portions thereon so as to form the unit elements, the unit elements being laminated on each other.
 19. The heat exchanging element of claim 1, wherein the primary airflow and the secondary airflow circulating the flow channels divided by the flow channel division portions are subjected to heat exchange in order of being at a right angle or an oblique angle to each other, being opposite to each other, and being at a right angle or an oblique angle to each other with the heat exchanger plates therebetween.
 20. The heat exchanging element of claim 1, wherein the heat exchanging element has a rectangular picture plane in a lamination direction, inlet ports of the primary airflow on a short side, inlet ports of the secondary airflow on the other short side, and outlet ports of the primary airflow and outlet ports of the secondary airflow on a long side.
 21. The heat exchanging element of claim 13, wherein the projections are high on an opening side and low on an inner side. 